Blasting-powder composition



Patented Dec. 1: 1925.

UNITED STATES PATENT. OFFICE.

cam, 12. PRATT, or TAMAQUA, PENNSYLVANIA, AssIGNon To ATLA IPANY, 0F WILMINGTON, DELAWARE, A CORPORATION OF DELKWARE.-

IBIiASTING-POWDER' COMPOSITION.

No Drawing.

To all whom it may concern Be it known that CARL D. PRATT, citizen of the United States, residing at Tamaqua, in the county of Schuylkill and State of Pennsylvania, has invented certain new and useful Improvements in Blasting-Powder Compositions, of which the following is a. speclficatlon.

' My invention relates to improvements in blasting powder compositions and it has for its object to provide a new and highly useful commercial blasting explosive which will possess characteristics of safety far beyond those of ordinary black blasting powder. I I

The record of the Bureau of Mines of the United States, covering the period from .by the Bureau of Mines.

1908 11:0 1923 shows that seventy-one coal mine explosions have been caused directly by the use of black blasting powder or by black blasting powder and dynamite, killing more than eight hundred men, injuring many others and causing untold property damage. This serious situation can be largely corrected 'by the substitution for black blasting powder, of what are known as permissible explosives, that is, explosives which have passed certain tests prescribed by said bureau, and verified in actual coal mining operations, have demonstrated 'conclusively that a permissible explosive has a very much shorter and cooler flame than black blasting powder and a very much COulBI' flame than other high explosives.

With the foregoing facts in mind it has been my aim to provide a series of blasting powder compositions, which have decreased tendencies, compared with current conmercial grades of blasting powder compositions, to ignite inflammable gases and dusts,

or mixtures thereof; as for example, those I occurring in coal-mines.

It should be expressly understood that my invention is not concerned with so-oalled high explosives, but is concerned entirely with the type of so-called low explosives,

herein referred to'as blasting powders.

Application filed May 31,

Tests conducted 1924. Serial N0. 717,141.. 7

High explosives include both individual compounds and mixtures of ingredients, which are able to suddenly decompose in the manner of a detonation, through almost instantaneous disintegrations and reactions,

"as influenced by heat or shock or both.-

Low explosives, on the other hand, consist only of mixtures of ingredients, of such a nature as to react with each other, in the form of a rapid combustion, as distinguished from a sudden disintegration, when influencedby heat.' It is a peculiarity of high explosives that they decompose with a s rownan commuch higher speed than low explosives,

thus exerting quicker and more disruptive actions than the slower and consequently more propulsive low explosives.

My improved blasting. powders may, properly, be referred to as safety blasting powders, since they are safer foruse under gaseous and dusty conditions, such as coalmlning, than the current blasting powders,

just as permissible" high explosives are safer for use in coal-mines than straight nitroglycerlne dynamites or gelatins.

As a result of a very exhaustive study or many princi'ples and extensive experimentatlon in following opt these principles in a .very large number of mixtures, I have.

been able to devise a series of blasting powders, w1th decreased tendencies (compared wlth current commercial blasting powders) to ignite inflammable gases and powders. of greater amounts of carbon and hydrogen in proportion with oxygen, to 'the extent of markedly decreasing the amounts of heat evolved by the decomposition reactions of such compositions.

I have also found that tartratcs and oxalates, such as sodium potassium tartrate, am-

- monium oxalate and the like, produce the desired decreased tendencies to ignite inflammable gases and dusts or mixtures thereof, when in intimate contact with the de composition reactions of blasting powder compositions,--especially those including one or more carbohydrates, through their heat absorbing abilities. 4

Further, I have discovered that blasting powder compositions, including carbohydrates, together with 'tartratcs and oxalates, selected in combination, or singly, to suit requirements, together with the usual blasting powder ingredients (metallic nitrates, sulphur and materials that are essentially carbon), will actually have several times less tendency to, ignite inflammable gases and dusts or mixtures thereof, than the current commercial grades of blasting powders. That is, charges of my safety blasting powders (hereinbefore defined) that I am' able to fire into certain gases and dusts or mixtures thereof, without igniting them, are several times the weight ofcu'rrent commercial' blasting powder charges which will ignite the same gases and dusts or mixtures thereof, under like conditions.

It should be expressly understood that the scope of my invention is broad enough to include any manner of introduction of the cooling ingredients; namely ,carbohydrates, taitrates and oxalates. That is, the said cooling ingredient or ingredients may be introduced in various manners, to suit conditions; as for instance," actual incorporation with the other ingredients or incorporation with only a portion of the other ingredients or included .as separate granules but mixed w th granules of the other in redients or with the grains of commercia grades of blasting powders, etc.

It should also be expressly understood that the scope of my invention 'is not limited to any particular physical form of safety blasting powders. That is, the physical form of said fsafety blasting powders may -vary 1n any manner whatsoever, to suit commercial application; as for instance,grannles,pellets, powders, cubes, cylinders, etc.

Summarizing, my safety blasting powders consist of one or more carbohydrates in any practicable quantity (preferably from. 5 to 35%) together with one or more tartrates and oxalates (preferably from 1 to 15%), used in combination or 'singly with practicable combinations of metallic .nitrates, sulphur and materials that are essentially carbon. Other ingredients may also be added to the above in minor variations of their densities, granulations,

quantities and still be within the scope of my invention, such as organic or inorganic compounds, that will absorb heat through the reduction of oxygen or by their volatilization during the decomposition reactions or by their liberation of water or crystallization or combination of such causes.

Typical formulae, .by way of examples,

are:

Ammonium oxalate My investigations indicate that I may vary the physical characteristics of my improved safety blasting powders through physical forms, etc., and produce similar effectiveness to the grades of blasting powders, now in the coal-mines of the United States, with the advantage of being much less aptito cause the very terrible coal-mine disasters that occur when the inflammable gas and dust mixtures, contained therein, are ignited. I may also see fit to add other ingredients to my safety blasting powders, as hereinbefore defined,'in order to produce the most desirable combinations of effectiveness and safety.

If carried into eifec't,'through substitution of the above described safety blasting powders for all the present types of so-called blasting powders, used in American coal mines, my invention will cause the improvement, hereinbefore described, of over 70% of all the explosives, used for .blasting coal in the United States.

(See United States Bureau of Mines Technical Paper 340-page-9.)

Having described -my invention, What I claim is:

1. A composition consisting of one or' more metalic nitrates, sulphur and one or more materials that are essentially carbon, the whole constituting a black blasting powder to which combination is added from 5 to 35% of one or more carbohydrates and 1 to 15% of one or more tartrates and oxalates. v

2. A composition consisting of one or more metallic nitrates,'sulphur and one or more materials that are essentially carbon, the whole constituting a black blastin powder to which combination is added om 5 to" 35% starch and sugar and 1 to 15% sodlium potassium tartrate and ammonium oxa ate.

3. A blasting powder consisting of from sodium nitrate, 5% sulphur, 17% charcoal, 45% to 65% sodium nitrate, from 1 to 15% 17% starch, and 7% sodium potassium tarsulphur and from 10 to 25% charcoal, to trate. which combination is added from 10 to 30% In testimony whereof he aflixes his signastarch and 1 to 10% sodium potassium'tarture.

crate.

4. A blasting powder, consisting of 54% CARL D. PRATT. 

